Fluid-actuated vibrator with helically-shaped fluid passageways

ABSTRACT

A free-rotor vibrator of the class which includes an outer case containing an internal cylindrical race wherein there orbits a free rotor of lesser diameter. Actuating fluid at relatively high pressure and exhaust fluid at relatively low pressure are respectively supplied to the rotor and exhausted therefrom simultaneously at both ends thereof in order to provide power for the orbital propulsion of the rotor. This is accomplished by providing helically-shaped passages between the race and the case, whereby the radical centrifugal forces of the rotor are resisted by helically-shaped separators, there always being at least one which resists the cantilever-type flexure of the race between the separators.

United States Patent Malan 1131 3,661,361 1 May 9,1972

[54] FLUID-ACTUATED VIBRATOR HELICALLY-SHAPED FLUID PASSAGEWAYS [72] Inventor: George Lester Malan, 560 East Rowland,

Covina, Calif. 9l722 [22] Filed: 7 Sept. 18,1970 [2l] Appl.No.: 73,409

[52] us. c1. .f. ..2s9/1n, 2s9/o1c1.43

[51] lnt.Cl. "B0" 11/00 [58] FleldofSearch ..2S9/lR,DlG. 43

[56] References Cited UNITE. STATES PATENTS 2,743,096" 4/1956 M65114." .259/1'11" 2,988,337 6/1961 Malan.... ..2s9/1 R 3,129,925 4/l964 Malall ..2s9/1 R 3,171,634 3/1965 M6166 ..2s9/1 R 3,282,570 1 H1966 Malan ..259/l R Primary Examiner-Walter A. Schcel Assistant E.\-aminer Philip R. Coe

Attorney-Angus & Mon

[57] ABSTRACT A free-rotor vibrator of the class which includes an outer case containing an internal cylindrical race wherein there orbits a free rotor of lesser diameter. Actuating fluid at relatively high pressure and exhaust fluid at relatively low pressure are respectively supplied to the rotor and exhausted therefrom simultaneously at both ends thereof in order to provide power for the orbital propulsion of the rotor. This is accomplished by providing helically-shaped passages between the race and the case, whereby the radical centrifugal forces of the rotor are reisisted by helically-shapedj separators, there always being at least one which resists the cantilever-type flexure of the race between the separators.

4 Claims, .3 Drawing Figures FLUlD-ACTUATED VIBRATOR WITH HELICALLY- SHAPED FLUID PASSAGEWAYS This invention relates to free rotorvibrators of the class generally shown in Malan U.S. Pat. Nos. 2,743,090, 2,988,337, and 3,129,925, issued Apr. 24, 1956, June 13, 1961, and Apr. 21, 1964, respectively. It is a function of this class of vibrator that fluid under a relatively elevated pressure is utilized to cause a freely rotating rotor to roll and orbit around the inside of a cylindrical race inside a case. The resulting radial centrifugal forces create an alternating pulse which is useful in settling in place plastic material such as concrete being poured into dams.

The Malan vibrator is a classical device which is well known in the darn building art. It is a device of substantial mass and power, but it is kept as small as possible in order that it may be handled by only one man. A classical vibrator of this type weighs about 80 pounds, has an outer diameter on the order of between 6 and 8 inches diameter and a rotor of about 4 inches diameter orbiting inside a race of about inches diameter. in such a device, pneumatic pressures on the order of 100 psi are utilized, exhausting to atmosphere.

In order to achieve the desired frequencies onthe order of 4,0007,000 cycles per minute, a substantial throughput of fluid isrequired. In order to make this flow pass through the restricted channels involved, in this class of vibrator, it is necessary to supply the fluid in as many locations and through as many of these channels as possible. As it happens, because of the forces and dimension involved in the geometry of the system, this means supplying and exhausting fluids at both ends of the rotor. I

While the supply and exhaust of fluids may seem to'be a simple matter, it does involve a number of quite serious complications. In the classical Malan devices, the race in which the rotor rotates is cylindrical on the inside and slotted on'the outside, the slots being axial. These axial slots provide for fluid communication for both pressure and exhaust connections between the two ends of the vibrator. This construction has worked quite well in practice and has been in use for a number Pat. No. 2,988,337, issued June 13, 1961, entitled Vibrator." Suffice it to say, and whatever their construction, their ultimate objective is to cause a rotor 20 having an outer bearing surface 21 and an outer diameter 22 to orbit in rolling contact with a cylindrical race 23 having an inner diameter 24. The race has a first central axis 25 and the rotor has a second central axis 26. Because the rotor is of lesser diameter, and is in rolling orbiting contact with the race, these axes will always be offset in operation and the orbiting operation of the rotor will cause centrifugal radial forces to be developed which are utilized as vibratory forces.

The fluid under pressure is made available to the system at a central region 27 in a first end face 28 and by means of a channel 29 to a radially outer region which will be more fully discussed below. Exhaust fluid is collected at a peripheral groove 30'which by channel 31 is connected to exhaust line 15. It will be noted that a central region 27a and a groove 30a are provided in a second end face 32, both end faces being adjacent to the rotor. The end faces are mirror images of each other. in a classical embodiment of the Malan vibrator, the rotor has a first and second end face 33, 34 wherein a fluid transfer occurs, but this is not the only technique wherein the race construction of this invention may be used to good advantage. Another example will be found in Malan U.S. Pat. No. 3,282,570, issued Nov. 1, 1966. The means of distributing the fluid within the rotor is not important to this invention. Sufiice it to say that his the objective of this invention to interconnect peripheral grooves 30 and 30a and central regions 27 and 27d within the case by means which will permit a structural integrity not heretofore known.

It will be noted that the race 23 is fonned on a race ring 35 which is fitted inside a cavity 36 in the case. This cavity may conveniently be made cylindrical, and usually will be. On the external surface of the race ring, there is a plurality of separators 37. These separators are helically inclined and make a firmfluid sealing interconnection between the race ring and of years, but-over a period of time it has become'obvious that in providing such channels, the axially-oriented separators have acted as bridge abutments, permitting flexure tooccur in the walls of the race between them, and ultimately resulting in premature failure in the nature of cracks which generally extend parallel to the central axis'of the device. This is a primary source of service problems, and it is an object of this invention to overcome this problem.

According to this invention, a vibrator which includes an internal cylindrical race and a rotor of lesserdiameter adapted to orbit in bearing contact therewith is provided with channels extending from end to end of the case so asto make fluid connections at the opposite ends of the rotor. The passageways are formed helically by. helically-oriented separators, any axial section which includes a central axis of the case never intersecting less thanone of said separators. The result of this is that the forces of the rotor are always resisted by at least one of said separators and there is never a cantilever or beam-type effect on the web of the race thatextends between two adjacent separators. This eliminates the said service problem and the material failure, between the separators.

The invention will be fully understood from the following detailed description and the accompanying drawings, in which:

FIG. 1 is an axial section partly in cutaway cross-section;

no.2 is a cross-section taken at line 24 of no. 1; and

FIG. 3 is a side elevation of a portion of FIG. 1.

In FIG. 1 is shown a vibrator 10. according to the invention which includes a case 11 adapted to be submerged in a medium to be vibrated. At a first end 12 there are provided fluid connections 13. These connections are concentric and include a pressure line 14 and an outer exhaust line 15, both of which connect to the case. The use to which the elevated and reduced pressures are put are of no importance to this invention but may be fully learned from reference to Malan U.S.

the race. It is obvious that the separators could have been placed on the inside of the case instead, but this is a more difficult structure to build, and it is more convenient to maintain these devices if the entire race ring may merely be removed and replaced than if the separators had to be supported on an internal diameter within the case. The separators divide the space 38between the race ring and the case into a plurality of flow channels 39, 40 which may selectively be connected to the pressure line and the exhaust line as desired.

Reference to FIGS. land 2 will indicate that a line contact is made between the rotor and the race which extends on a line lying always in a plane which includes the central axis of the case, i.e., it lies on an axial section of the case. This plane, in any of its infinite number of positions, never intersects less than one of said separators (preferably, it will intersect a plurality of them as shown in the drawings), and this plane will never be intersected only by a web for the full axial length of the plane. This means that there is always a substantial buttressing support'to the region of contact between the rotor and the race, and there is no cantilever effect between two separators as in the priorart. It has been found that this arrangement materially decreases the requirement for replacement of the race and accordingly the maintenance of the vibrator is reduced to maintenance of proper relationships between the rotor and its associated mechanisms. The race. which will remain useful in its respective case for as long as its internal dimensions remain suitable.

This invention is not to be limited by the embodiments shown in the drawings and described in the description which is given-by way of example and not of limitation, but only in accordance with the scope of the appended claims.

I claim:

1. In a fluid-actuated free rotor vibrator of the class which includes an outer case intended for immersion. into a medium diameter, and a free rotor having an external cylindrical bearing surface with its own second central axis and second diameter, said second diameter being smaller than the said first diameter, the said rotor having a first and a second end facing respective ones of said end faces, it being a function of the vibrator that fluid is transferred from the case to the rotor, and returned to the case simultaneously at both of the said ends and end faces, the improvement of providing an internal peripheral surface in the case and an external peripheral surface on the race, these surfaces being radially spaced apart and providing a plurality of helicaliy-extending separators dividing the spacing between the said surfaces into flow channels, any axial section including the central axis of the case never intersecting less than one of said separators, and no said axial section intersecting only a web between two separators.

2. Apparatus according to claim 1 in which the separators are formed integrally with the race and fitted into a cylindrical cavity in the case.

3. Apparatus according to claim 1 in which the said axial section never intersects less than a plurality of said separators.

4. Apparatus according claim 3 in which the separators are formed integrally with the race and fitted into a cylindrical cavity in the case.

I I I. F i 

1. In a fluid-actuated free rotor vibrator of the class which includes an outer case intended for immersion into a medium to be subjected to vibratory forces, a pair of internal inwardly-facing end faces mounted to said case, an internal cylindrical race mounted to said case having a first central axis and a first diameter, and a free rotor having an external cylindrical bearing surface with its own second central axis and second diameter, said second diameter being smaller than the said first diameter, the said rotor having a first and a second end facing respective ones of said end faces, it being a function of the vibrator that fluid is transferred from the case to the rotor, and returned to the case simultaneously at both of the said ends and end faces, the improvement of providing an internal peripheral surface in the case and an external peripheral surface on the race, these surfaces being radially spaced apart and providing a plurality of helically-extending separators dividing the spacing between the said surfaces into flow channels, any axial section including the central axis of the case never intersecting less than one of said separators, and no said axial section intersecting only a web between two separators.
 2. Apparatus according to claim 1 in which the separators are formed integrally with the race and fitted into a cylindrical cavity in the case.
 3. Apparatus according to claim 1 in which the said axial section never intersects less than a plurality of said separators.
 4. Apparatus according claim 3 in which the separators are formed integrally with the race and fitted into a cylindrical cavity in the case. 